Definition #1 - The stupidest fucking cunt living in Pittsburgh, his asshole expands to the star size of Texas and the strip of the Byzantine Empire, and when he poses for Goatsee, his anus screams Ave Maria.

Definition #2 - The underside of a typical male testical. Commonly known for being darker than the males scrotum. When people refer to "Tessius", they often do so without realizing it.

Definition #3 - The act of covering one's cock in shit and puke.

Example given for definition #1:
Bitch 1: Did you just see that big fat fucking Tessius?
Bitch 2: How could I fucking miss it? I heard it giving a sermon as it walked by.

Example given for definition #3:
Hick 1: "So I was telling this dumb blond to shut the fuck up and she pulled a Tessius after I shoved my dick in her ass and pulled out in just enough time for her to eat the shit off of it. She vomited all over my cock.
Hick 2: Did she finish?
Hick 1: You fucking know she did.
Hick 1 & 2 high five.